A record-breaking heat wave is intensifying concerns over America's expanding data centers as officials warn that surging electricity demand from artificial intelligence infrastructure is straining the nation's electric grid.
The Department of Energy on Tuesday authorized PJM Interconnection, the regional grid operator serving 13 states and Washington, D.C., to potentially require data centers to switch to backup diesel generators if necessary to prevent blackouts during the extreme heat.
The emergency measure comes as electricity demand is expected to reach a record 166 gigawatts Thursday, surpassing the previous all-time high set in 2006.
Many of those backup generators emit pollutants that the Environmental Protection Agency classifies as possible human carcinogens.
"This is exactly what we expect in a warming world," Brown University climate scientist Kim Cobb told Politico.
"Even a modest increase in baseline temperature causes an exponential increase in heat extremes. You find yourself crossing these heat extremes much more frequently."
Virginia, home to the world's largest concentration of data centers, sits at the center of the debate.
State regulators have approved more than 8,000 diesel generators for data centers in recent years, with one-third of facilities located within 500 feet of homes or schools.
PJM recently updated its emergency procedures to account for soaring electricity demand from data centers.
Calling on the facilities to use backup generators is considered a last-resort measure after voluntary conservation requests.
Aaron Tinjum, vice president of energy for the Data Center Coalition, told the outlet facilities "will work closely with utilities and grid operators, using backup power if directed and where appropriate to reduce strain on the grid and ensure Americans and first responders remain connected to the services they rely on."
While PJM says it expects to have enough electricity generation to meet demand, experts warn the longer-term outlook is increasingly challenging.
"It's scary. It worries everyone when you see those kind of numbers," said Abe Silverman, a former New Jersey utility regulator.
He added that future projections for data center electricity demand "dwarf the amount of data center load we have now."
Energy Secretary Chris Wright blamed the strained grid on the previous Biden administration, saying the Trump administration is "using every available tool ensuring Americans in the mid-Atlantic have continued access to affordable, reliable, and secure energy to power and cool their homes."
Residents living near Virginia's data centers say they are caught between the risk of blackouts and exposure to diesel emissions.
"Nothing says life, liberty, and the pursuit of happiness like breathing in diesel fumes," said Elena Schlossberg, who leads a grassroots group opposing data center expansion in Prince William County.
"Either way, we are screwed. Either our lights go out or we get to breathe in this pollution."
Last summer, residents near Ashburn reported dark plumes of smoke from data center generators during a heat wave.
Sierra Club of Virginia official Ann Bennett said concerns are even greater this year after regulators approved nearly 3,800 additional diesel generators in 2025.
"This time, we are all anxiously anticipating what is going to happen, and we have thousands more generators to worry about," Bennett said.
The controversy reflects a broader shift in public opinion toward the AI-driven data center boom, where both conservatives and liberals find a rare area of agreement.
Critics on the left have focused on the industry's enormous electricity and water consumption, air pollution from backup generators, and environmental impacts, while conservatives have increasingly questioned whether massive taxpayer incentives and infrastructure investments are justified as AI automates white-collar jobs and threatens employment.